A power storage device pack includes a housing and a power storage device module fixed to the housing. The power storage device module includes a plurality of power storage devices arranged in one direction, a pair of binding members configured to bind the power storage devices at both ends in the one direction, an elastic member arranged between one of the binding members and one of the power storage devices and configured to absorb expansion of the power storage devices, and a plurality of heat-transfer plates arranged so as to respectively make contact with the power storage devices. A plurality of heat-conduction members are configured to respectively conduct heat from the heat-transfer plates to the housing, and a plurality of sliding members respectively joined to first ends of the heat-conduction members and relatively slidable in the one direction, are arranged between the heat-transfer plates and the housing.